The gun used on the T33 (in the initial wartime order) was the 75mm M6 gun from the M24 chaffee. Weight-wise, this weighs 400~ lbs vs the 890~ lbs for the 75mm M3 gun on the "traditional" Sherman; meaning more room and stuff for other things in the turret.

By October 1945, when everything was turned over by Standard Oil to CWS for post-war development; the gun was now the 75mm M17; a slightly modified version of the 75mm M6, but with a muzzle brake.

And the actual # of vehicles being envisioned for the "Wartime" program was 600. But that ended when Japan surrendered.

I noticed an error on the icons. I had the travel lock on the front slope. So, I corrected that and since I was working on this, I put the M17 75mm gun on it also. I called that version the T33E1 for you Mark.